wiki:WARPnet1/BuildClientScripts

This page describes WARPnet v1.0, which supports the OFDM Reference Design. For experiments with the 802.11 Reference Design please refer to WARPnet 2.0

Building and Running WARPnet 1.0 Scripts

Here we will build and run a client script. To see a complete example refer to the example script.

Building the Client Script

Synchronizing Structs

There are two files that the user control over as the build their custom scripts to control the boards. The first is warpnet_client_experiment_structs.py. This file defines the data structures that are sent back and forth between the FPGA design and the client script. The FPGA design and this file must be in sync for data to be accurately transferred between the two. Let us look at an example to understand how this file is built. The following is the ControlStruct that is used to set basic node parameters. First we see the C struct that is stored in the FPGA.

#define STRUCTID_CONTROL 0x13
#define STRUCTID_CONTROL_ACK 0x14

typedef struct {
    char structID;
    char nodeID;
    char txPower;
    char channel;
    char modOrderHeader;
    char modOrderPayload;
    short reserved;
    int pktGen_period;
    int pktGen_length;
} warpnetControl;

typedef struct {
    char structID;
    char nodeID;
    short cmdID;
} warpnetAck;

The next is the ControlStruct as seen in warpnet_client_experiment_structs.py.

STRUCTID_CONTROL = 0x13
STRUCTID_CONTROL_ACK = 0x14

class ControlStruct(ClientStruct):
    txPower = -1
    channel = -1
    modOrderHeader = -1
    modOrderPayload = -1
    reserved = 0
    packetGeneratorPeriod = 0
    packetGeneratorLength = 0
    
    def __init__(self, logger=None):
        ClientStruct.__init__(self, logger)
        self.structID = STRUCTID_CONTROL
        self.expectedReturnStructID = STRUCTID_CONTROL_ACK
        self.txPower = 63
        self.channel = 4
        self.modOrderHeader = 0
        self.modOrderPayload = 2
        self.packetGeneratorPeriod = 10
        self.packetGeneratorLength = 1300
    
    def prepToSend(self, nodeID):
        self.updateDone = False
        return struct.pack('!6BH2I', self.structID, nodeID, self.txPower, self.channel, self.modOrderHeader, \
                self.modOrderPayload, self.reserved, self.packetGeneratorPeriod, self.packetGeneratorLength)
        
    def updateFromNode(self, rawData, pcapts):
        dataTuple = struct.unpack('!BBH', rawData[0:4])

The prepToSend function creates the raw data that is seen by warpnet.c in the FPGA. It creates a byte packed data of 6 bytes (6B), 1 short (H) and 2 ints (2I). This is exactly what the node is expecting. A appropriate response from the node is a warpnetACK which updateFromNode parses in the python file.

For a struct that is requesting data the raw data sent would be a warpnetRequest struct and expect a response of the appropriate type.

Logging Data

As statistics are received by the client, there is good chance that the data would want to be written to a file. There is a built in method to do this. In the top-level script create a DataLogger object like the following.

 dataLog = DataLogger('filename.txt', fileRefreshTime)

The fileRefreshTime is the the interval after which Python will automatically write the file to disk and re-open it. This is very useful when running long tests as the data is constantly being stored even in the event of an error or power outage.

To log data to the file pass a formatted string to the DataLogger instance. For example:

 dataLog.log('Data=%d' % (valueToStore))

Running the Client Script

  1. Once the client script has been written, navigate to the folder where it is located.
  2. Run the following:
     python experiment.py
    
Last modified 8 years ago Last modified on Feb 12, 2014, 11:19:32 AM